<?php
/**
* The MIT License
* Copyright (c) 2006 Johan Nilsson http://johan.galaxen.net/ http://markupartist.com
*
* Permission is hereby granted, free of charge, to any person obtaining a copy 
* of this software and associated documentation files (the "Software"), to deal 
* in the Software without restriction, including without limitation the rights 
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
* copies of the Software, and to permit persons to whom the Software is 
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all 
* copies or substantial portions of the Software.
* 
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 
* SOFTWARE.
*/

/**
 * Iterator for arrays that implements the SPL interface Iterator.
 * 
 * @author Johan Nilsson
 */
class Base_Iterator implements SeekableIterator
{
	protected $_list  = null;
	protected $_pointer= 0;
	protected $_keys = array();

	/**
	 * Constructor
	 *
	 * @param array $list
	 */
	public function __construct(array $list)
	{
		$this->_list = $list;
		$this->_keys = array_keys($this->_list);
	}

	/**
	 * Returns the current item.
	 *
	 * @return mixed
	 */
	public function current()
	{
		return $this->_list[$this->key()];
	}

	/**
	 * Move internal pointer forward.
	 * 
	 * @return void
	 */
	public function next()
	{
		$this->_pointer ++;
	}

	/**
	 * Retrive the current key.
	 *
	 * @return mixed
	 */
	public function key()
	{
		return $this->_keys[$this->_pointer];
	}

	/**
	 * Reset the internal pointer.
	 *
	 * @return void
	 */
	public function rewind()
	{
		$this->_pointer = 0;
	}

	/**
	 * Checks if we have more items to traverse.
	 * 
	 * @return boolean
	 */
	public function valid()
	{
		return $this->_pointer < count($this->_list);
	}

	/**
	 * Set iterator to a given position.
	 *
	 * @param int $pointer
	 * 
	 * @throws OutOfBoundsException
	 * 
	 * @return void
	 */
	public function seek($pointer)
	{
		$this->rewind();
		$position = 0;

		while($position < $pointer && $this->valid()) 
		{
			$this->next();
			$position++;
		}

		if (!$this->valid()) 
		{
			throw new OutOfBoundsException('Invalid seek position');
		}	
	}
}